Aloe peel-derived honeycomb-like bio-based carbon with controllable morphology and its superior electrochemical properties for new energy devices.

Abstract In this study, aloe peel-derived honeycomb-like porous carbons (AP-HC) are controllably prepared by combining simple hydrothermal carbonization with chemical activation. A morphology transformation from the spherical structure (AP-SC) to the honeycomb-like structure (AP-HC) is achieved for biomass-derived carbon materials and is accompanied by an increase in the specific surface area from 13 to 1286 m2 g−1. The AP-HC as a counter electrode (CE) for dye-sensitized solar cells (DSSCs) exhibits remarkable catalytic activity for I 3 - ion reduction and a high power conversion efficiency (PCE) of 6.92% that matches the Pt-based DSSC's performance (7.19%). As a working electrode in supercapacitors (SCs), a high specific capacitance of 264 F g−1 at 0.5 A g−1 is achieved in a three-electrode system. Additionally, a high retention rate of ∼77.45% (ranging from 0.5 to 30.0 A g−1) and superior cycling performance (91% capacitance retention after 5000 cycles) are also demonstrated. This study provides an efficient strategy for fabricating morphology-controllable porous bio-based carbon with higher specific surface area (1286 m2 g−1) that exhibits significant potential for new energy devices. Graphical abstract fx1 Highlights • Honeycomb-like carbon (AP-HC) is prepared by modified hydrothermal method. • Controllable morphology transformation is realized in bio-based carbon. • A high specific surface area of 1286 m2 g−1 is obtained for AP-HC. • A PCE of 6.92% is achieved in DSSCs with biomass-derived carbon catalyst. • AP-HC demonstrates excellent electrochemical performances (264 F g−1) in SCs. [ABSTRACT FROM AUTHOR]